1. Field of the Invention
The present invention is directed to a method for processing thin wafers and solar cells of the type composed of crystalline silicon.
2. Description of the Prior Art
Solar cells of crystalline silicon (C--Si) are widespread for terrestrial use. The demands made of solar cells for environmental compatibility, large-area produceability, high efficiency and reasonable cost have been well satisfied by these solar cells. Compared to thin-film solar cells of amorphous silicon (A--Si:H), copper-indium (gallium)diselenide (CIS, CGS) and cadmium telluride (CdTe), however, they also have a few disadvantages.
Crystalline silicon is extremely brittle and, consequently, is easily broken. Manipulatable wafers of C--Si or solar cells manufactured of this material must currently have a thickness of approximately 300 .mu.m in order to be able to assure a reliable processing and manipulatibility due to the significant risk of breakage. Due to the fragility, the shaping of the wafer had to hitherto be undertaken by a suitable edging of the C--Si single-crystal rod, i.e. even before the sawing of the wafer. Individualized shaping for a single wafer or for a single solar cell is therefore not possible or is only possible with great outlay.
Heretofore, it was not possible to apply solar cells produced of crystalline silicon on highly curved surfaces without this leading to a breakage of the solar cells. Although European Application 0 221 287 discloses a method with which solar cells of crystalline silicon can be embedded between a slightly curved carrier and a uniformly arced glass pane using specific laminating technique. This method, however, is limited to surfaces having no more than a slight arc such as, for example, the roof of a motor vehicle.